diff --git a/chain/actors/actor_miner.go b/chain/actors/actor_miner.go
index a55010669..cd282c949 100644
--- a/chain/actors/actor_miner.go
+++ b/chain/actors/actor_miner.go
@@ -467,7 +467,12 @@ func (sma StorageMinerActor) SubmitFallbackPoSt(act *types.Actor, vmctx types.VM
 		return nil, aerrors.HandleExternalError(lerr, "could not load proving set node")
 	}
 
-	faults, nerr := self.FaultSet.AllMap()
+	ss, lerr := amt.LoadAMT(types.WrapStorage(vmctx.Storage()), self.Sectors)
+	if lerr != nil {
+		return nil, aerrors.HandleExternalError(lerr, "could not load proving set node")
+	}
+
+	faults, nerr := self.FaultSet.AllMap(ss.Count)
 	if nerr != nil {
 		return nil, aerrors.Absorb(err, 5, "RLE+ invalid")
 	}
@@ -937,7 +942,12 @@ func onSuccessfulPoSt(self *StorageMinerActorState, vmctx types.VMContext) aerro
 		return aerrors.HandleExternalError(nerr, "failed to load proving set")
 	}
 
-	faults, nerr := self.FaultSet.All()
+	ss, nerr := amt.LoadAMT(types.WrapStorage(vmctx.Storage()), self.Sectors)
+	if nerr != nil {
+		return aerrors.HandleExternalError(nerr, "failed to load proving set")
+	}
+
+	faults, nerr := self.FaultSet.All(ss.Count)
 	if nerr != nil {
 		return aerrors.Absorb(nerr, 1, "invalid bitfield (fatal?)")
 	}
diff --git a/chain/types/bitfield.go b/chain/types/bitfield.go
index d959e4f84..a9498d3b9 100644
--- a/chain/types/bitfield.go
+++ b/chain/types/bitfield.go
@@ -1,6 +1,7 @@
 package types
 
 import (
+	"errors"
 	"fmt"
 	"io"
 
@@ -9,6 +10,8 @@ import (
 	"golang.org/x/xerrors"
 )
 
+var ErrBitFieldTooMany = errors.New("to many items in RLE")
+
 type BitField struct {
 	rle rlepluslazy.RLE
 
@@ -106,7 +109,14 @@ func (bf BitField) Count() (uint64, error) {
 }
 
 // All returns all set bits
-func (bf BitField) All() ([]uint64, error) {
+func (bf BitField) All(max uint64) ([]uint64, error) {
+	c, err := bf.Count()
+	if err != nil {
+		return nil, xerrors.Errorf("count errror: %w", err)
+	}
+	if c > max {
+		return nil, xerrors.Errorf("expected %d, got %d: %w", max, c, ErrBitFieldTooMany)
+	}
 
 	runs, err := bf.sum()
 	if err != nil {
@@ -121,7 +131,14 @@ func (bf BitField) All() ([]uint64, error) {
 	return res, nil
 }
 
-func (bf BitField) AllMap() (map[uint64]bool, error) {
+func (bf BitField) AllMap(max uint64) (map[uint64]bool, error) {
+	c, err := bf.Count()
+	if err != nil {
+		return nil, xerrors.Errorf("count errror: %w", err)
+	}
+	if c > max {
+		return nil, xerrors.Errorf("expected %d, got %d: %w", max, c, ErrBitFieldTooMany)
+	}
 
 	runs, err := bf.sum()
 	if err != nil {